How they work
A garage floor shelter is a steel unit set into a pit cut into the garage slab. A heavy sliding lid covers the opening, flush with the floor. When it's closed you can typically park on it. When storms threaten, you slide the lid open, climb down, and close it from inside.
Installation, and the rock question
- Site check and 811 locate. The installer checks the slab, layout and utilities.
- Cut and excavate. The slab is saw-cut and the pit dug. In much of Rutherford County, this is where limestone may appear.
- If rock is hit, the installer may need to break it with a hydraulic hammer, which adds time and cost. Occasionally rock is too shallow and a different shelter type makes more sense.
- Set, anchor and re-pour. The shelter is placed, leveled and locked into new concrete.
- Finish and test the lid, seals and any opener.
Ask how the quote handles rock: is there a fixed price, an hourly rate for rock work, or a way out if the dig isn't practical?
Capacity
Plan for at least 3 square feet per person (the ICC 500 residential minimum). Many models hold roughly 4 to 12 people.
Things to plan for
- Parking. You can't open the lid with a car on top. Plan where vehicles sit on storm nights.
- Steps. Climbing down can be hard for some family members. An above-ground room may suit them better.
- Getting out. If debris blocks the lid, you may need help. Register your shelter with Rutherford County Emergency Management if a registry is available, and keep a charged phone and radio inside.
- Water. Ask about lid seals and drainage, especially if your garage floor slopes toward the shelter.
Questions to ask
- Is the model, including the lid and locks, tested to ICC 500 / FEMA P-361?
- Is the manufacturer NSSA-verified?
- Can the lid be opened from inside without power?
- How will you handle rock if you hit it?